In order to make the cut, Funk says a company must demonstrate that its sustainability strategy can significantly add to shareholder value in terms of revenue growth, cost improvements, and customer loyalty.

Microsoft (MSFT), Visa (V), and American Tower (AMT) all fit the bill. They’re among the fund’s 34 stock holdings and, according to Funk, are successfully making the connection between long-term sustainability strategy and long-term business strategy.

One of the fund’s biggest winners has been Ecolab (ECL), the maker of cleaning chemicals for restaurants and other industries. Funk likes the way Ecolab has invested in research and development to reduce the amount of water and energy needed to clean dishes.

Another top holding is Google’s parent company, Alphabet (GOOG). Funk says its data centers are 50% more energy-efficient than its rivals because it optimizes the way data is stored and accessed.

Amazon (AMZN) also made the grade. Funk admits the company has plenty of risks including its carbon-footprint and labor issues, but she cites its fast-growing Web services business as a reason to own the stock.

“Companies don’t have to build their own data centers and manage all that energy. They can use Amazon’s IT infrastructure in order to have all that computational power available to them.”

You won’t find Tesla (TSLA) in Funk’s sustainability fund. She highlights the electric car maker’s disappointing cash flow as one reason why, as well as doubts about its scalability.